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Acute cooling of the feet and onset of common cold symptoms

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There is a common folklore that chilling of the body surface causes the development of common cold symptoms, but previous clinical research has failed to demonstrate any effect of cold exposure on susceptibility to infection with common cold viruses. This study will test the hypothesis that acute cooling of the feet causes the onset of common cold symptoms. 180 healthy subjects were randomized to receive either a foot chill or control procedure. All subjects were asked to score common cold symptoms, before and immediately after the procedures, and twice a day for 4/5 days. 13/90 subjects who were chilled reported they were suffering from a cold in the 4/5 days after the procedure compared to 5/90 control subjects (P=0.047). There was no evidence that chilling caused any acute change in symptom scores (P=0.62). Mean total symptom score for days 1-4 following chilling was 5.16 (+/-5.63 s.d. n=87) compared to a score of 2.89 (+/-3.39 s.d. n=88) in the control group (P=0.013). The subjects who reported that they developed a cold (n=18) reported that they suffered from significantly more colds each year (P=0.007) compared to those subjects who did not develop a cold (n=162). Acute chilling of the feet causes the onset of common cold symptoms in around 10% of subjects who are chilled. Further studies are needed to determine the relationship of symptom generation to any respiratory infection.
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doi:10.1093/fampra/cmi072
Acute cooling of the feet and the onset of
common cold symptoms
Claire Johnson and Ronald Eccles
Johnson C and Eccles R. Acute cooling of the feet and the onset of common cold symptoms.
Family Practice 2005; 22: 608–613.
Background. There is a common folklore that chilling of the body surface causes the develop-
ment of common cold symptoms, but previous clinical research has failed to demonstrate any
effect of cold exposure on susceptibility to infection with common cold viruses.
Objective. This study will test the hypothesis that acute cooling of the feet causes the onset of
common cold symptoms.
Methods. 180 healthy subjects were randomized to receive either a foot chill or control pro-
cedure. All subjects were asked to score common cold symptoms, before and immediately after
the procedures, and twice a day for 4/5 days.
Results. 13/90 subjects who were chilled reported they were suffering from a cold in the 4/5
days after the procedure compared to 5/90 control subjects (P = 0.047). There was no evidence
that chilling caused any acute change in symptom scores (P = 0.62). Mean total symptom score
for days 1–4 following chilling was 5.16 (±5.63 s.d. n = 87) compared to a score of 2.89 (±3.39 s.d.
n = 88) in the control group (P = 0.013). The subjects who reported that they developed a cold
(n = 18) reported that they suffered from significantly more colds each year (P = 0.007) compared
to those subjects who did not develop a cold (n = 162).
Conclusion. Acute chilling of the feet causes the onset of common cold symptoms in around
10% of subjects who are chilled. Further studies are needed to determine the relationship of
symptom generation to any respiratory infection.
Keywords. Cold exposure, common cold, infection, nose.
Introduction
The common cold is a mild self-limiting illness usually
confined to the upper respiratory tract.
1
The disease is
self-diagnosed from a range of symptoms such as nasal
stuffiness, sneezing, throat irritation and mild fever.
2
There is a common folklore that associates the develop-
ment of symptoms of common cold with exposure to a
cold environment, and that the onset of a cold is a direct
result of wet clothes, feet and hair.
3
Throughout the
clinical literature of the last three hundred years
there have been many reports that acute cooling of
the body surface causes the onset of symptoms of com-
mon cold, and historically it has been generally accep-
ted that acute exposure to cold is a direct cause of these
symptoms.
4,5
However, studies involving inoculation of cold
viruses into the nose and periods of cold exposure
have failed to demonstrate any effect of cold exposure
on susceptibility to infection with common cold
viruses.
6–8
Although modern textbooks of virology dis-
miss any cause-and-effect relationship between cold
exposure and common cold as erroneous folklore,
9
the
belief is so widespread and longstanding it is difficult
to completely dismiss this idea as having no validity.
In 1919 Mudd and Grant studied the reactions of the
nasal mucosa in response to chilling the body surface
and showed that cooling the body surface causes a
reflex vasoconstriction of blood vessels in the nose
and a decrease in temperature of the mucous mem-
brane.
10
They speculated that this reflex vasoconstric-
tion of the airway epithelium could decrease resistance
to infection and allow bacterial infection of the ton-
sils.
10
Some years later Sir Christopher Andrewes sug-
gested that exposure to a cold environment may trigger
the development of a cold but only in people who are
carrying the latent cold virus.
6
Eccles developed
these early observations by proposing a hypothesis
that acute cooling of the body surface causes a reflex
Received 8 November 2004; Accepted 31 May 2005.
Common Cold Centre, Cardiff School of Biosciences, Cardiff
University, Cardiff CF10 3US, UK. Correspondence to
Professor Ronald Eccles, Common Cold Centre, Cardiff
School of Biosciences, Cardiff University, Cardiff CF10
3US, UK; Email: eccles@cardiff.ac.uk
608
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vasoconstriction in the nose and upper airways, and this
vasoconstrictor response may inhibit respiratory
defence and cause the onset of common cold symptoms
by converting an asymptomatic viral infection (sub-
clinical infection) into a symptomatic viral infection
(clinical infection).
11
The novel idea in this hypothesis
was that when common cold viruses are circulating in
the community a proportion of those infected will have
sub-clinical infections, and that when any of this sub-
group are exposed to chilling of the body surface this
could aid conversion of a sub-clinical infection to a clin-
ical infection. This study was aimed at testing this hypo-
thesis, by studying the onset of common cold symptoms
after acute chilling of healthy asymptomatic subjects,
during the winter, when common cold viruses are cir-
culating in the community.
The aims of the study were to determine if acute chil-
ling caused: acute onset of common cold symptoms
within minutes of chilling; delayed onset of common
cold symptoms over a 4/5 days period after chilling;
the perception that the subjects were suffering from
a common cold over a 4/5 days period after chilling.
The study also aimed to investigate any relationship
between the history of colds incidence in the previous
year and the onset of common cold symptoms.
Methods
Subject population
180 healthy subjects were recruited from the student
population of Cardiff University. All subjects attended
the Common Cold Centre, Cardiff. All procedures were
carried out under standard conditions at a room tem-
perature of eighteen to twenty-five degrees centigrade.
Subjects were not permitted to smoke or consume food
or drink during the study period. All subjects were
given a patient information leaflet to read and were
asked to sign the consent form. After signing the con-
sent form the subjects completed a questionnaire about
their medical history and their suitability for inclusion
into the study was checked. Subjects were deemed suit-
able for inclusion in the study if the subject was over
eighteen years old and healthy as determined by med-
ical history. Subjects were not enrolled in the study if
the subject had suffered with acute upper respiratory
tract infection in the previous two weeks, or if the sub-
ject had a history of seasonal or perennial rhinitis.
Experimental procedures
Once enrolled into the study subjects were randomized
to receive chilling or control procedures. A computer
generated randomization list was used to assign subjects
to either the chill or control procedure with subjects
stratified according to the number of common colds
reported by the subject in the previous year. Subjects
with 0–3 colds in the previous year were allocated to the
next available procedure at the start of the randomisa-
tion list and subjects with 4 or more colds were assigned
to the next available procedure at the end of the list.
Ninety subjects were allocated to receive the chill pro-
cedure and ninety subjects to receive the control pro-
cedure. If allocated to the chilling procedure, the
subject was asked to remove their shoes and socks
and place their feet in a bowl containing 9–10 litres
of water at a temperature of 10
C for twenty minutes.
The temperature of the cold bath was monitored
(Pen shape digital multi-stem thermometer, Scientific
Laboratory Supplies Ltd, Wilford Industrial Estate,
Nottingham, UK) and ice was added if necessary to
maintain the water temperature at 10
C. If allocated
to the control procedure the subject was asked to
keep their shoes and socks on and place their feet in
an empty bowl for twenty minutes. Warm water was not
used as a control as it was believed that this stimulus
could have influenced nasal blood flow.
Symptom scores
All subjects were asked if they were suffering with a
cold and to score symptoms of runny nose, blocked
nose, sore throat, sneezing and cough on a scale of
0–3 with 0 = not present, 1 = mild, 2 = moderate, 3 =
severe before and immediately after the procedure. The
same common cold question and symptom scores were
also used in a daily diary. The method of symptom
scores has been widely used in previous studies on com-
mon cold.
12,13
All subjects were provided with a diary,
in which they were instructed to score symptoms and at
the same time to indicate if they believed they were
suffering from a common cold (day 1 PM, days 2 and
3 AM/PM, day 4 AM, and on visit two which occurred
on day 4 or 5).
Nasal airflow was measured as a Nasal Partitioning
Ratio (NPR) as described by Cuddihy and Eccles
14
before the procedures and on day 4/5 using the GM
NV1 spirometer (GM Instruments Ltd, Unit 6
Ashgrove, Ashgrove Rd, Kilwinning, Scotland, UK).
NPR was believed to be useful as an objective measure
to confirm the presence of acute rhinitis. However the
measurements of NPR proved to be too variable to pro-
vide any meaningful data and these results are not
presented in the present paper.
Previous history of colds
As part of the clinical history subjects were asked how
many colds they had suffered from in the previous year.
Statistics
This was a pilot study and it was therefore not possible
to perform a power calculation, but the ratio of sub-
clinical to clinical infection was considered in order
to determine the sample size required for the study.
It was predicted that 29 subjects in the chilled group
would develop colds and 9 subjects in the control
Acute cooling of the feet and the onset of common cold symptoms 609
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group giving a maximum difference between the groups
of 20 and a minimum of 10 depending on the distribu-
tion of spontaneous colds. Statistical comparisons were
made between the two experimental groups of subjects;
chilled and control. The hypotheses were tested at a
0.05 level of significance. The Mann-Whitney test
was used to test for differences in symptom scores
and history of colds incidence. The immediate effects
of chilling were studied by comparing the differences
from baseline to immediately after the test procedures
in total symptom scores, between chilled and control
groups. The delayed effects of chilling were studied
by comparing the differences in total symptom scores
between chilled and control groups over the 4/5 days
period after the test procedures. Mean total symptom
scores have been used to describe the symptom score
data in the text as this descriptive shows a change in the
symptom score, whereas the median does not due to the
large number of zero scores. The total symptom scores
(days 1 + 2 + 3 + 4/5, maximum score 120) were also ana-
lysed as dichotomous data using the Chi-squared test,
with total scores of 0–8 indicating absence of a cold and
9–120 indicating presence of a cold. The Chi-squared
test was used to test for differences in the number of
colds reported by the two test groups in their diaries. A
subject was deemed to have experienced a cold if they
reported they were suffering from a cold on any occa-
sion after the test procedures on days 1 + 2 + 3 + 4/5.
Results
Subject demographics
180 subjects were enrolled in the study between
October 2003 and March 2004, 90 were randomized
to the chill procedure, and 90 to the control procedure.
The flow diagram in Figure 1 shows the flow of parti-
cipants through each stage of the study. The demo-
graphics of the two test groups are provided in Table 1
that demonstrates that the test groups were balanced
and there was no significant difference in any of the
baseline characteristics.
Acute effects of chilling
The test procedures did not cause any significant
changes in symptom scores, and all the mean scores
Assessed for eligibility
(n=188
)
Randomised
(n=180
)
Excluded (n=8)
Not meeting inclusion
criteria (n=4)
Refused to participate
(n=4
)
Allocated to chill
procedure (n=90)
Received chill
procedure (n=90)
Allocated to control
procedure (n=90)
Received control
procedure (n=90
)
Lost to follow-up:
3 subjects returned
to the centre later
than day 5
Lost to follow-up:
2 subjects returned to
the centre later than
day
5
Analysed (n=90)
Excluded from analysis
where comparisons we re
made on results drawn
from day 4/5 (n=3)
Analysed (n=90)
Excluded from analysis
where comparisons we re
made on results drawn
from day 4/5 (n=2
)
FIGURE 1. Flow of subjects through each stage of the study
610 Family Practice—an international journal
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were close to zero indicating few or no symptoms were
present before or immediately after the procedures as
illustrated in Table 2. The small difference in symptom
scores between the two groups prior to the procedures
was not significant (P = 0.245). The difference in total
symptom score pre and post chill procedure was not
significantly higher than the difference in total symp-
tom score pre and post control procedure (P = 0.62).
Delayed effects of chilling
Table 3 shows the mean daily scores and total score for
days 1 to 4/5 following each procedure. Total symptom
scores for days 1–4/5 following the chill procedure
(5.16 ± 5.63 s.d.) were significantly higher than the total
symptom scores for days 1–4/5 following the control
procedure (2.89 ± 3.39 s.d.) (P = 0.013). When the total
symptom scores for the 4/5 days were analysed as dicho-
tomous data, 26/90 (28.8%) of the chilled subjects and
8/90 (8.8%) of the control subjects were deemed to be
suffering from a cold (total symptom score 9–120), and
this difference was significant (P = 0.001).
The total number of subjects that reported they were
suffering from a common cold in their diaries during the
4/5 days following the chill or control procedures is
shown in Figure 2 and this illustrates that significantly
more subjects believed they were suffering from a cold
in the chilled group (13/90, 14.4%) compared to the
control group (5/90, 5.6%, P = 0.047). There was no
sex difference in the development of colds with 9.3%
of males and 10.3% of females developing colds (P =
0.828, Chi-squared). Of those in the chilled group that
developed colds 4/13 were male (31%) and 9/13 female
(69%), but this sex difference merely reflects the pro-
portions of males (28%) and females (72%) exposed to
the chill procedure and is not significant (P = 0.749,
Fisher Exact).
Colds history in previous year
There was no difference in colds incidence between the
two test groups at baseline as illustrated in Table 1.
However, when looking at both test groups combined,
those subjects who believed there were suffering from a
cold had a history of more colds each year (median 2.00,
range 1–10) compared to those who did not develop a
cold (median 3.00, range 2–8, P = 0.007).
Discussion
Acute effects of chilling
The present study provides no evidence for an acute
effect of chilling on the development of common
cold symptoms. Symptom scores were close to zero
in both the control and chilled groups.
TABLE 2 Immediate effects of chilling
Baseline Immediately
after
procedure
Difference Statistics
Control
(n = 90)
0.02
(0.15)
0.13
(0.37)
0.11
(0.35)
Comparison
of differences
P = 0.62 (MW)
Chill
(n = 90)
0.07
(0.29)
0.21
(0.51)
0.14
(0.41)
Figures are mean (standard deviation) of total symptom scores, before
and immediately after control and chill procedures. Differences are
differences from baseline.MW = Mann Whitney test.
TABLE 1 Demographics of test groups
Control n = 90 Chill n = 90 Significance
Median age
(range)
20.0 (18–43) 20.0 (18–39) P = 0.598 (MW)
Male 29 25 P = 0.515
(Chi-squared)
Female 61 65
Median colds
per year (range)
2.0 (1–10) 2.0 (1–8) P = 0.859 (MW)
MW = Mann Whitney test.
0
30
60
90
Control Chilled
subjects
FIGURE 2. Numbers of subjects that reported they were
suffering from a common cold in their diaries during the 4/5
days period following control or chill procedures. The
shaded area represents those subjects reporting colds
TABLE 3 Delayed effects of chilling
Day 1 Day 2 Day 3 Day 4/5 Total Statistics
Control
(n = 88)
mean score
0.32
(0.70)
0.73
(1.11)
0.48
(0.77)
1.36
(1.95)
2.89
(3.39)
Comparison
of total
symptom
scores
P = 0.013
Chill
(n = 87)
mean score
0.57
(1.12)
1.38
(1.84)
1.28
(1.48)
1.93
(2.83)
5.16
(5.63)
Figures are mean (standard deviation) of daily symptom scores and
total scores for days 1–4/5 following each procedure.
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Delayed effects of chilling
A delayed effect of chilling on the incidence of colds
and symptoms was observed in the 4/5 days following
the chill procedure. Significantly more chilled subjects
than control subjects reported they were suffering from
colds in the 4/5 days following the test procedures. The
difference in the incidence of colds between the two test
groups was also supported by a significant difference in
total symptom scores over the 4/5 days following the
test procedures. Analysis of the symptom scores as
dichotomous data also demonstrated a significantly
greater symptom score (more colds) in the chilled
group. The increased incidence of reports of colds
and higher symptom scores in the chilled subjects
compared to the control subjects may be due to several
factors.
Belief in the folklore that acute chilling of the body
surface, in some way precipitates a common cold could
have caused some bias in the reporting of colds and
symptoms. The subjects were not questioned about
their beliefs but the idea was introduced and then dis-
missed in the informed consent information in the fol-
lowing way:
‘‘This study is designed to investigate the effects of
acute chilling on the development of common cold
symptoms. It is a popular belief that the develop-
ment of an upper respiratory tract infection such as
the common cold is a result of a chill. However,
previous studies have failed to demonstrate that
exposure to a cold environment increases the incid-
ence of the common cold. ... Common cold
symptoms are very common during the winter per-
iod and it is expected that some subjects will
develop symptoms because they have been previ-
ously exposed to infected persons. Therefore the
development of any common cold symptoms
may be unrelated to any experimental procedures
in this study’’.
If the common cold symptoms reported after chilling
were solely a result of subject bias caused by belief
in the effects of chilling then one would have expected
an acute effect of chilling on the scoring of common
cold symptoms rather than a delayed effect.
The differences between the chilled and control
groups could have occurred as a chance finding, as it
was expected that some subjects would develop cold
symptoms due to natural exposure to common cold
viruses. The probability value for the different report-
ing of colds was just below P = 0.05 (P = 0.047) but the
P-value for the difference in total symptom scores was
more convincing with P = 0.013, and for the dichotom-
ous analysis was P = 0.001. With two different measures
of the incidence of common cold providing significant
differences between the two test groups it is unlikely
that the results are solely due to chance.
Chilling of the feet in cold water (12
C±1
C) has
been previously reported to cause an intense vasocon-
striction of both the cutaneous and upper airway blood
vessels
15
and the vasoconstriction of the upper airways
has been proposed as a mechanism that reduces respir-
atory defence against infection.
10,11
When common cold
viruses are circulating in the community a proportion of
subjects will have sub-clinical infections, and chilling of
these subjects may cause vasoconstriction in the upper
airway epithelium and conversion of a sub-clinical to a
clinical infection. In these cases the subject links the
causality of the common cold symptoms to the chill
and does not realise that they were already infected
before they ‘caught’ a cold. Laboratory studies using
viral challenge and cold exposure do not provide any
evidence that chilling increases susceptibility to the
development of common cold symptoms
7,8
but these
studies do not mimic the natural exposure to common
cold viruses and they can be criticised for the small
numbers of subjects used to power the studies.
An interesting finding in the present study was that
the subjects who reported they developed a cold after
the chill or control procedures also reported that they
suffered from significantly more colds each year, than
the subjects who did not report a cold after the proced-
ures. This finding may indicate that there is a sub popu-
lation in the general population who are more
susceptible to developing common cold symptoms
each year and that they may have a ‘common cold con-
stitution’.
16
The results of the present study demonstrate that
chilling is associated with the onset of common cold
symptoms but the study does not provide any objective
evidence, such as virology, that the subjects were infec-
ted with a common cold virus. Because of the great
variety of viruses causing the common cold syndrome
it is difficult to identify the causative agent responsible
for common cold symptoms in any subject when viruses
are circulating in the community. For this reason it was
decided to first study the relationship between chilling
and symptoms, and then to consider the use of virology
in a subsequent study.
In summary the results of the present study support
the folklore that exposure to chilling may cause the
onset of common cold symptoms, perhaps by some
change in respiratory defence caused by reflex vasocon-
striction of the blood vessels of the upper airways. Fur-
ther studies in this area are needed to determine if the
development of common cold symptoms following cold
exposure are associated with infection.
Declaration
Funding: the study was funded by Cardiff University.
The study sponsor had no involvement in the study
design, the collection, analysis and interpretation of
612
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by guest on June 4, 2013http://fampra.oxfordjournals.org/Downloaded from
data, in the writing of the report or in the decision to
submit for publication. The corresponding author had
full access to all the data in the study and had final
responsibility for the decision to submit for publication.
Ethical approval: the study was approved by the South
East Wales Local Research Ethics Committee.
Conflicts of interest: none.
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... Several factors contribute to these thermoregulatory disturbances, including neurovascular, psychosocial, cultural, environmental, and medical [1,3,4,7]. Cold extremities not only contribute to thermal dis-comfort [1] and a reduced quality of life [3,4,6,7], but they can also impair sleep quality and onset of sleep [6,8], facilitate the onset of common cold symptoms [9,10], and contribute to the development of various other diseases [3,6]. In Western medicine, cold extremities without an identifiable cause or underlying disease, such as peripheral neuropathy or hypothyroidism, are often considered as not warranting treatment [6] or remain untreated due to the lack of satisfactory approaches [7]. ...
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Objective: Warm footbaths infused with Sinapis nigra (mustard, or MU) or Zingiber officinale (ginger, or GI) are used for various thermoregulatory conditions, but little is known about how they are perceived by individuals, both short- and long-term. We analyzed the immediate and long-term effects of MU and GI on warmth and stimulus perception in healthy adults. Methods: Seventeen individuals (mean age 22.1±2.4 years; 11 female) received three footbaths (mean temperature was 40 ± 0.2 ℃, administered between 1:30-6:30pm) in a randomized order with a cross-over design: 1. with warm water only (WA), 2. with warm water and MU and 3. with warm water and GI. Warmth and stimulus perception at the feet were assessed at the 1st, 5th, 10th, 15th, and 20th minute of the footbaths, in the late evening (EVE), and the following morning (MG). We further assessed well-being (at EVE and MG) and sleep quality (at MG). The primary outcome measure was the warmth perception at the feet at the 10th minute of the footbath. Results: At the 10th minute of the footbath, warmth perception at the feet was significantly higher with MU and GI compared to WA. The immediate thermogenic effects pointed to a quick increase in warmth and stimulus perception with MU, a slower increase with GI, and a gradual decrease with WA. Regarding the long-term effects, warmth and stimulus perception were still higher after GI compared to WA at EVE and MG. No differences were seen for general well-being and sleep quality. Conclusion: Thermogenic substances can significantly alter the dynamics of warmth and stimulus perception when added to footbaths. The different profiles in the application of GI and MU could be relevant for a more differentiated and specific use of both substances in different therapeutic indications.
... Further, although immersing just the feet in cold water has been found to increase URTI incidence (8) , Cold Swimmers suffered similar URTI to the other groups. ...
Article
It has long been claimed that non-wetsuit cold water swimming (CWS) benefits health (1), and anecdotally cold-water swimmers claimed to suffer fewer and milder infections, though this was not directly measured. A boost to immunity is biologically plausible: stress hormones are released during cold-water immersion (2), and short-term stress may ready the immune system for injury or infection (3). However, very few studies have investigated immune system markers and/or actual illness in habitual cold-water swimmers.
... Available experimental evidence suggests that salivary IgA levels 72 are influenced by lifestyle and environmental factors, such as exercise 5 , stress 6 , dietary 73 intake 7,8 , and temperature 9 . A previous study investigating temperature showed that 74 exposure of the feet to cold increased the incidence of common cold onset 10 . This finding 75 suggests that cold environments may weaken immune system barriers, which has a negative 76 impact on preventing the common cold. ...
Article
Background: In countries with mild winter climates and inadequate heating, the relationship between housing conditions and health outcomes in winter have not been well studied. The purpose of present study was to evaluate the relationship between heater type and temperature factors in the bedroom and incidence of the common cold among children in Japan. Methods: In this prospective cohort study, we distributed baseline questionnaires and temperature loggers in December 2019 and administered follow-up questionnaires in March 2020. We recruited children under age 15 years. We performed Poisson regression analysis and logistic regression analysis. Results: Of 297 participants, air conditioners were the most prevalent (n=105, 35%), followed by gas or kerosene heaters (n=50, 17%) and floor heaters (n=31, 10%). Air-conditioners were associated with higher incidence of all events related to the common cold, especially having a fever (adjusted incidence rate ratio (aIRR)=1.84, 95% confidence interval (CI): 1.41-2.40). Contrary, gas or kerosene and floor heaters showed a lower incidence rate of some events related to the common cold, such as school or nursery school absence (aIRR=0.55, 95% CI: 0.37-0.82 and aIRR=0.39, 95% CI: 0.23-0.67, respectively). Whereas bedroom temperature did not show a positive association, children who always felt cold showed a higher incidence of some events related to the common cold. Conclusions: Our findings imply that the heating approach and modal thermal comfort, such as location of heating appliances, humidity, airflow, and radiant heat, may be more important for the onset of common cold in children than bedroom temperature itself.
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Objectives: Respiratory tract infections (RTIs) are extremely common, usually self-limiting, but responsible for considerable work sickness absence, reduced quality of life, inappropriate antibiotic prescribing and healthcare costs. Patients who experience recurrent RTIs and those with certain comorbid conditions have higher personal impact and healthcare costs and may be more likely to suffer disease exacerbations, hospitalisation and death. We explored how these patients experience and perceive their RTIs to understand how best to engage them in prevention behaviours. Design: A qualitative interview study. Setting: Primary care, UK. Methods: 23 participants who reported recurrent RTIs and/or had relevant comorbid health conditions were interviewed about their experiences of RTIs. Interviews took place as the COVID-19 pandemic began. Data were analysed using inductive thematic analysis. Results: Three themes were developed: Understanding causes and vulnerability, Attempting to prevent RTIs, Uncertainty and ambivalence about prevention, along with an overarching theme; Changing experiences because of COVID-19. Participants' understandings of their susceptibility to RTIs were multifactorial and included both transmission via others and personal vulnerabilities. They engaged in various approaches to try to prevent infections or alter their progression yet perceived they had limited personal control. The COVID-19 pandemic had improved their understanding of transmission, heightened their concern and motivation to avoid RTIs and extended their repertoire of protective behaviours. Conclusions: Patients who experience frequent or severe RTIs are likely to welcome and benefit from advice and support regarding RTI prevention. To engage people effectively, those developing interventions or delivering health services must consider their beliefs and concerns about susceptibility and prevention.
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Background: The association between temperatures and respiratory diseases has been extensively reported. However, the associated healthcare costs and attributable fractions due to temperature have scarcely been explored. The aims of this study were to estimate respiratory disease hospitalization costs attributable to non-optimum ambient temperature, to quantify the attributable fraction from cold and hot temperatures, and to estimate the future hospitalization costs in two Australian cities. Methods: The associations between daily hospitalization costs for respiratory diseases and temperatures in Sydney and Perth over the study period of 2010-2016 were analyzed using distributed lag non-linear models. Future hospitalization costs for respiratory diseases were estimated based on three predicted climate change scenarios - RCP2.6, RCP4.5 and RCP8.5. Results: The estimated respiratory disease hospitalization costs attributable to non-optimum ambient temperatures increased from 493.2 million Australian dollars (AUD) in 2010s to more than 700 million AUD in 2050s in Sydney, and from 98.0 million AUD to about 150 million AUD during the same period in Perth, in large part due to population growth. In the context of climate change, the current cold attributable fraction in Sydney (23.7%) and Perth (11.2%) is estimated to decline by the middle of this century to (18.1-20.1%) and (5.1-6.6%) respectively, while the heat-attributable fraction for respiratory disease is expected to gradually increase from 2.6% up to 5.5% in Perth. Conclusions: This study found both cold and hot temperatures increased the overall hospitalization costs for respiratory diseases in two major Australian cities, although the attributable fractions varied. The largest contributor was cold temperatures. While respiratory disease hospitalization costs will increase in the future, climate change will result in a decrease in the cold attributable fraction and an increase in the heat attributable fraction, depending on the location.
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Article
Objective To analyze the thermogenic effects of footbaths with medicinal powders in oncological patients (ON) and healthy controls (HC). Intervention and Outcomes Thirty-six participants (23 ON, 13 HC; 24 females; 49.9 ± 13.3 years) received 3 footbaths in a random order with cross-over design: warm water only (WA), warm water plus mustard (MU, Sinapis nigra), and warm water plus ginger (GI, Zingiber officinale). Warmth perception of the feet (Herdecke Warmth Perception Questionnaire, HeWEF) at the follow-up (10 minutes after completion of footbaths, t2) was assessed as the primary outcome measure. Secondary outcome measures included overall warmth as well as self-reported warmth (HeWEF) and measured skin temperature (high resolution thermography) of the face, hands and feet at baseline (t0), post immersion (t1), and follow-up (t2). Results With respect to the warmth perception of the feet, GI and MU differed significantly from WA ( P’s < .05) with the highest effect sizes at t1 (WA vs GI, d = 0.92, WA vs MU, d = 0.73). At t2, perceived warmth tended to be higher with GI compared to WA ( d = 0.46). No differences were detected between ON and HC for self-reported warmth. With respect to skin temperatures, face and feet skin temperatures of ON were colder (at t0 and t1, 0.42 ≥ d ≥ 0.68) and tended to have diametrical response patterns than HC (ON vs HC: colder vs warmer after MU). Conclusion Among adult oncological patients and healthy controls, footbaths with mustard and ginger increased warmth perception of the feet longer than with warm water only. The potential impact of regularly administered thermogenic footbaths over extended periods merits further investigation for the recovery of cancer-related sense of cold.
Article
Las infecciones de las vías respiratorios altas (IVRA), son debilitantes para el potencial deportivo de los atletas de élite. El ejercicio físico activa múltiples vías moleculares y bioquímicas relacionadas con el sistema inmune, sensibles a influencias nutricionales. Sobre este contexto, la inmunonutrición está adquiriendo una nueva dirección orientada a conseguir el equilibrio inmunológico, contraponiéndose con algunas de las teorías que han sentado las bases de la inmunología del ejercicio durante las últimas décadas. Objetivo. Investigar los aspectos nutricionales que puedan mejorar la respuesta inmunológica en deportistas de elite. Estudiar los posibles beneficios del equilibrio inmunológico para mejorar el rendimiento, analizar los factores nutricionales que contribuyan al equilibrio de la respuesta inmunológica y extrapolar la evidencia actual en recomendaciones prácticas de alimentación/suplementación para mejorar la homeostasis de la respuesta inmunológica en atletas de élite, teniendo en cuenta las limitaciones existentes.Resultados. La evidencia científica apunta que se puede potenciar el equilibrio inmunológico y la respuesta inmune a través de la modificación de factores nutricionales. Dentro de los cuales, la vitamina D, los probióticos, la vitamina C y el cinc son los que cuentan con mayor evidencia. Conclusión. Los avances científicos resultan prometedores y de interés para los atletas de élite, debido a que pueden disminuir la incidencia de IVRA, mejorando el éxito deportivo de los mismos. Se requieren más estudios para su validación y aplicación.
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This review seeks to explain three features of viral respiratory illnesses that have perplexed generations of virologists: (1) the seasonal timing of respiratory illness and the rapid response of outbreaks to weather, specifically temperature; (2) the common viruses causing respiratory illness worldwide, including year‐round disease in the Tropics; (3) the rapid arrival and termination of epidemics caused by influenza and other viruses. The inadequacy of the popular explanations of seasonality is discussed, and a simple hypothesis is proposed, called temperature dependent viral tropism (TDVT), that is compatible with the above features of respiratory illness. TDVT notes that viruses can spread more effectively if they moderate their pathogenicity (thereby maintaining host mobility) and suggests that endemic respiratory viruses accomplish this by developing thermal sensitivity within a range that supports organ‐specific viral tropism within the human body, whereby they replicate most rapidly at temperatures below body temperature. This can confine them to the upper respiratory tract and allow them to avoid infecting the lungs, heart, gut etc. Biochemical and tissue‐culture studies show that ‘wild’ respiratory viruses show such natural thermal sensitivity. The typical early autumn surge of colds and the occurrence of respiratory illness in the Tropics year‐round at intermediate levels are explained by the tendency for strains to adapt their thermal sensitivity to their local climate and season. TDVT has important practical implications for preventing and treating respiratory illness including Covid‐19. It is testable with many options for experiments to increase our understanding of viral seasonality and pathogenicity.
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Introduction Three Lines of Defense As we face the COVID-19 pandemic and other viruses such as the flu, many wonder what they can do to avoid getting infected or to minimize the effects if they become ill. In general, there are some primary lines of defense against a virus. SELF-DEFENSE The first line of defense includes actions you can take to keep yourself healthy and strengthen your immune system. This can include proper hygiene, good self-care, and possible supplementation. While self-defense may not completely protect you from being infected, it may help reduce the duration or impact of the infection. TREATMENT DEFENSE Medical treatments that have been found effective against COVID-19 or other viruses can provide a third line of defense. This may include pharmaceuticals, medical devices, or therapies, typically administered in a clinical setting such as a hospital, urgent care clinic, or medical office. All these lines of defense are important in order to protect the greatest number of people. The first line of defense—self-defense—is the focus of this document. Medical treatment defense are beyond the scope of this document and will not be addressed.
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There is a widely held belief that acute viral respiratory infections are the result of a "chill" and that the onset of a respiratory infection such as the common cold is often associated with acute cooling of the body surface, especially as the result of wet clothes and hair. However, experiments involving inoculation of common cold viruses into the nose, and periods of cold exposure, have failed to demonstrate any effect of cold exposure on susceptibility to infection with common cold viruses. Present scientific opinion dismisses any cause-and-effect relationship between acute cooling of the body surface and common cold. This review proposes a hypothesis; that acute cooling of the body surface causes reflex vasoconstriction in the nose and upper airways, and that this vasoconstrictor response may inhibit respiratory defence and cause the onset of common cold symptoms by converting an asymptomatic subclinical viral infection into a symptomatic clinical infection.
Chapter
Episodes of respiratory viral infection were recognized long before their causal agents were discovered, and viral epidemiology was one of the first branches of virology to be developed. Studies of respiratory viral epidemiology have been limited by the capabilities of the diagnostic methods available at the time. These have improved steadily over the years and are continuing to do so, particularly with the recent development of molecular methods of viral detection. Early studies tended to concentrate on those viruses that could be most easily detected using traditional methods, such as influenza viruses, adenoviruses and respiratory syncytial (RS) virus. As time passed rhinoviruses and coronaviruses were discovered, and as methods for their detection have improved, so has come an appreciation of their importance in respiratory viral illness. These two viruses are now thought to account for between 50% and 75% of upper respiratory tract infections, and as such, due emphasis will be given to these virus types in this chapter.
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The effect of exposure in a 4°C room and a 32°C water bath on experimentally induced rhinovirus Type 15 infection was studied in 44 antibody-free volunteers. Volunteers were exposed to cold at selected intervals: at inoculation; during incubation; during maximum illness; and during recovery. Infectivity, illness severity, quantitative virus-shedding patterns, antibody response, leukocyte response and bacteriologic flora of the upper respiratory tract were evaluated in subjects exposed to cold and in a similar number of controls. Although exposure to cold abolished the characteristic increase in neutrophils during illness, there were no significant changes in the other findings. Thus, this study demonstrated no effect of exposure to cold on host resistance to rhinovirus infection and illness that could account for the commonly held belief that exposure to cold influences or causes common colds.
Article
This paper outlines a widely-held conception of illness, related to perceived changes in body temperature--'Chills' and 'Colds' on one hand, 'Fevers' on the other---in an English suburban community on the outskirts of London. The relationship between this folk model, and that of the local family physicians is analysed, to show how biomedical treatment and concepts, particularly the germ theory of disease, far from challenging the folk model, actually reinforce it. Remedies which cannot be scientifically and biomedically justified are nevertheless prescribed by the physicians to meet their patients' need to 'make sense' of biomedical treatment in terms of their folk model of illness. At the interface between physicians and patient, biomedical diagnoses and treatment are more 'negotiable' than previously realised--and this has important implications for the delivery of health care.
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The common cold is one of the most frequently occurring illnesses and is responsible for substantial morbidity and economic loss. Biochemical evidence suggests that zinc may be an effective treatment, and zinc gluconate glycine (ZGG) lozenges have been shown to reduce the duration of cold symptoms in adults. To determine the efficacy of ZGG treatment of colds in children and adolescents. A randomized, double-masked, placebo-controlled study. Two suburban school districts in Cleveland, Ohio. A total of 249 students in grades 1 through 12 were enrolled within the first 24 hours of experiencing at least 2 of 9 symptoms of the common cold. Zinc lozenges, 10 mg, orally dissolved, 5 times a day (in grades 1-6) or 6 times a day (in grades 7-12). Time to resolution of cold symptoms based on subjective daily symptom scores for cough, headache, hoarseness, muscle ache, nasal congestion, nasal drainage, scratchy throat, sore throat, and sneezing. Time to resolution of all cold symptoms did not differ significantly between students receiving zinc (n = 124) and those receiving placebo (n = 125) (median, 9 days; 95% confidence interval [CI], 8-9 days; median, 9 days, 95% CI, 7-10 days, respectively; P=.71). There were no significant differences in the time to resolution of any of the 9 symptoms studied. Compared with controls, more students in the zinc group reported adverse effects (88.6% vs 79.8%; P=.06); bad taste (60.2% vs 37.9%; P=.001); nausea (29.3% vs 16.1%; P=.01); mouth, tongue, or throat discomfort (36.6% vs 24.2%; P=.03); and diarrhea (10.6% vs 4.0%; P=.05). In this community-based, randomized controlled trial, ZGG lozenges were not effective in treating cold symptoms in children and adolescents. Further studies with virologic testing are needed to clarify what role, if any, zinc may play in treating cold symptoms.
Article
Constitutional factors might play a role in the susceptibility to clinical illness during the common cold. This study seeks to determine if the likelihood of developing frequent common colds persists during childhood. The Tucson Children's Respiratory Study involves 1246 children enrolled at birth and followed prospectively since 1980 and 1984. Parents reported the occurrence of frequent (> or =4) colds during the past year by questionnaire at 2, 3, 6, 8, 11, and 13 years of age. Blood for ex vivo interferon-gamma responses was obtained at 9 months and 11 years of age. After adjustment for potential confounding variables, children with frequent colds at year 2 or 3 were twice as likely to experience frequent colds at year 6 (relative risk [RR], 2.8; 95% confidence interval [CI], 2.1-3.9), year 8 (RR, 2.6; 95% CI, 2.1-3.3), year 11 (RR, 2.4; 95% CI, 1.8-3.1), and year 13 (RR, 2.1; 95% CI, 1.4-3.3) compared with children who had infrequent colds at years 2 and 3. At 9 months of age, children who ultimately experienced persistent frequent colds had lower interferon-gamma titers than children without persistent frequent colds (3.05 +/- 1.61 vs 3.74 +/- 1.39, P =.016); this finding persisted at 11 years of age. These data suggest the existence of a common cold constitution, whereby some children are more susceptible to infection and/or the expression of clinical symptoms when infected than are other children.
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Despite great advances in medicine, the common cold continues to be a great burden on society in terms of human suffering and economic losses. Of the several viruses that cause the disease, the role of rhinoviruses is most prominent. About a quarter of all colds are still without proven cause, and the recent discovery of human metapneumovirus suggests that other viruses could remain undiscovered. Research into the inflammatory mechanisms of the common cold has elucidated the complexity of the virus-host relation. Increasing evidence is also available for the central role of viruses in predisposing to complications. New antivirals for the treatment of colds are being developed, but optimum use of these agents would require rapid detection of the specific virus causing the infection. Although vaccines against many respiratory viruses could also become available, the ultimate prevention of the common cold seems to remain a distant aim.